You want to add redundant (extra) gauges? Physically installing gages is easy, giving them a proper signal is not! That gauge requires a matching sending unit inside of your gas tank. Doing so is virtually impossible on plastic gas tank. Do you just want some blinking lights, or are you actually looking for information? You could plug in OBD2 style gauge (like Ultra Gauge) and it will give you LOTS of useful information!
If you want it to act like the stock one then you need one setup for 3 ohms at full, and 110 ohms at empty. Keep in mind that the stock gauge has a very long response time, I am often 5 miles down the road before it shows completely full after a fill-up.
If you want to have some fun get two gauges to mount side by side, but setup for 1 ohm at full and 55 ohms empty, with a fast response time. Connect one to each fuel sender and you can watch the fuel move from side to side in the curves. Would also help in the low-fuel situations where you have fuel in the low side of the tank, but your fuel pick-up is in the high side of the tank. You would know when to slosh fuel to the high side.
I guess you could get a Narrow band O2 sensor gauge. They are pretty cheap, flashy and you tap into your existing O2 sensor (no need for an extra sensor). The only useful thing it will tell you is condition of your O2 sensor (fast response is good, slow response is bad).